This project is a treatment-matching study to test whether adding antidepressant pharmacotherapy to behavioral cessation treatment improves the depression-prone smoker's ability to quit, while not undermining cessation goals for the smoker who lacks a history of depression. The study target is to randomize 120 smokers with a prior history of depression and 120 smokers who lack such a history to a double-blind treatment with either 60 mg fluoxetine or placebo, while they undergo cognitive behavioral treatment to quit smoking.